Development of large format photon-counting Geiger-mode avalanche photodiode (Gm-APD) focal plane arrays by MIT Lincoln Laboratory [1] has revolutionized airborne lidar 3D mapping capability. Lincoln Laboratory has developed multiple generations of Gm-APD based airborne lidar systems for US government customers that are capable of collecting 3D data from high-altitudes (> 6 km) with higharea collection rates (100’s km2/hr) at point densities (~ 100 point/m2) and vertical resolutions of 18 cm. These systems have been used operationally for a variety of missions that include humanitarian assistance and disaster relief, support for military operations and imaging under heavy forest canopy obscuration. This paper briefly reviews the key enabling technology, Gm-APD focal plane arrays and the airborne 3D remote sensing capabilities they enable. It then presents examples of how these systems have delivered operational impact across the aforementioned mission.

Redundancy resolution of redundantly actuated cable-driven parallel robots (CDPRs) requires the computation of feasible and continuous cable tension distributions along a trajectory. This paper focuses on n-DOF CDPRs driven by n + 2 cables, since, for n = 6, these redundantly actuated CDPRs are relevant in many applications. The set of feasible cable tensions of n-DOF (n + 2)-cable CDPRs is a 2-D convex polygon. An algorithm that determines the vertices of this polygon in a clockwise or counterclockwise order is first introduced. This algorithm is efficient and can deal with infeasibility. It is then pointed out that straightforward modifications of this algorithm allow the determination of various (optimal) cable tension distributions. A self-contained and versatile tension distribution algorithm is thereby obtained. Moreover, the worst-case maximum number of iterations of this algorithm is established. Based on this result, its computational cost is analyzed in detail, showing that the algorithm is efficient and real-time compatible even in the worst case. Finally, experiments on two six-degree-of-freedom eight-cable CDPR prototypes are reported.